This relates generally to imaging systems and, more particularly, to imaging systems having image sensor integrated circuit packages.
Modern electronic devices such as cellular telephones, cameras, and computers often use digital image sensors. Imagers (i.e., image sensors) often include a two-dimensional array of image sensing pixels. Each pixel typically includes a photosensitive element such as a photodiode that receives incident photons (light) and converts the photons into electrical signals.
In a typical arrangement, an image sensor die includes an image sensor integrated circuit formed on a front surface of the image sensor die and electrical contacts (e.g., a grid of solder balls) formed on a rear surface of the image sensor die. Through-silicon vias are used to electrically connect the image sensor integrated circuit on the front surface of the image sensor die to the electrical contacts on the rear surface of the image sensor die. The image sensor die is then mechanically and electrically coupled to a printed circuit board by soldering the electrical contacts on the rear surface of the image sensor die to the printed circuit board.
There are a number of disadvantages associated with this type of packaging arrangement. In particular, the image sensing pixels and other internal electronic components may not be sufficiently protected from external elements such as dirt, dust, and water. The performance of the image sensing pixels and the image sensor as a whole may be compromised if external elements are allowed to enter an image sensor package. For example, water that leaks into an image sensor package may decrease performance of the image sensor or cease the image sensor from functioning entirely.
It would therefore be desirable to provide improved ways of forming image sensor integrated circuit packages.